A photoacoustic wave diagnostic apparatus is an apparatus in which, when a living body which is a test portion to be tested is irradiated with light, an image is displayed based on a detection signal of an acoustic wave (typically an ultrasonic wave) generated by thermal expansion of a measuring object. By this diagnostic apparatus, a specific material in the test portion, such as glucose or hemoglobin contained in blood or the like, is tested.
In the photoacoustic wave diagnostic apparatus, a probe is used to receive an acoustic wave. When an air layer is present between the probe and a living body and/or when the acoustic impedance of the probe is significantly different from that of a living body, an acoustic wave is reflected at the interface therebetween. For this reason, it is necessary to provide an acoustic matching material having acoustic properties similar to those of human tissues between the probe and a living body. In PTL 1, an acoustic matching material used for an acoustic wave probe and a manufacturing method thereof have been disclosed, the acoustic matching material having acoustic properties similar to those of human tissues and being formed from a base material of an elastomer or a resin and a composite powder having a higher acoustic impedance than that of the base material.
In addition, in a medical diagnostic apparatus, for the purposes of accuracy control and training of engineers, a human tissue model called a human tissue simulation material (hereinafter, referred to as a “phantom” in some cases) has been used. As a material for the phantom, a material which has properties similar to those of human tissues and which can be stored for a long period of time without causing, for example, the growth of bacteria has been desired.
In addition, PTL 2 has disclosed a non-corrosive acoustic wave phantom which has acoustic properties similar to those of human tissues and which is obtained by dispersing a powdered organic filler in a urethane resin functioning as a base material.